Biological Activity

Icotinib inhibits EGFR activity in a dose-dependent manner, with an IC50 value of 5 nM and complete inhibition at 62.5 nM. Icotinib selectively solely inhibits the EGFR members including the wild type and mutants with inhibition efficacies of 61-99%. Icotinib blocks EGFR-mediated intracellular tyrosine phosphorylation in human epidermoid carcinoma A431 cells in a dose-dependent manner. Meanwhile, in our proliferation assay performed on A431, BGC-823, A549, H460, HCT8, KB and Bel-7402 cell lines, we found that the relative sensitivity of cell lines to Icotinib is A431 > BGC-823 > A549 > H460 > KB > HCT8 and Bel-7402. Icotinib exhibits a broad spectrum of antitumor activity and it is especially effective against tumors expressing higher levels of EGFR. [1]

In vivo

Icotinib shows an antitumor effect in different types of xenografts. Icotinib inhibits tumor growth at a rate of 51.5%, 31.0% and 67.4% in the A431, A549 and H460 xenografts at a dose of 120 mg/kg, respectively. [1]

Features

Protocol(Only for Reference)

In the in vitro kinase assays, 2.4 ng/μL EGFR protein is mixed with 32 ng/μL Crk in 25 μL kinase reaction buffer containing 1 μM cold ATP and 1 μCi 32P-γ-ATP. The mix is incubated with Icotinib at 0, 0.5, 2.5, 12.5 or 62.5 nM on ice for 10 min followed by incubation at 30 °C for 20 min. After quenching with SDS sample buffer at 100 °C for 4 min, the protein mix is resolved by electrophoresis in a 10% SDS-PAGE gel. The dried gel is then exposed to the PhosphorImager to detect radioactivity. Quantification is performed by ImageQuant software. In this methodology the radioactive signal inversely correlates with kinase activity.

Cells (103 /well) are seeded into 96-well plates in RPMI-1640 medium containing 10% FBS and grown in a 5% CO2 incubator at 37 °C. After 24 h, cells are treated with Icotinib at 0, 0.78, 1.56, 3.125, 6.25, 12.5 or 25 μM for 96 h. Cell proliferation is calculated by subtracting the mean absorbance value on day 0 from the mean absorbance value on day 4.

Conversion of different model animals based on BSA (Value based on data from FDA Draft Guidelines)

Species

Mouse

Rat

Rabbit

Guinea pig

Hamster

Dog

Weight (kg)

0.02

0.15

1.8

0.4

0.08

10

Body Surface Area (m2)

0.007

0.025

0.15

0.05

0.02

0.5

Km factor

3

6

12

8

5

20

Animal A (mg/kg) = Animal B (mg/kg) multiplied by

Animal B Km

Animal A Km

For example, to modify the dose of resveratrol used for a mouse (22.4 mg/kg) to a dose based on the BSA for a rat, multiply 22.4 mg/kg by the Km factor for a mouse and then divide by the Km factor for a rat. This calculation results in a rat equivalent dose for resveratrol of 11.2 mg/kg.

* <1 mg/ml means slightly soluble or insoluble.* Please note that Selleck tests the solubility of all compounds in-house, and the actual solubility may differ slightly from published values. This is normal and is due to slight batch-to-batch variations.

Erlotinib is an EGFR inhibitor with IC50 of 2 nM, >1000-fold more sensitive for EGFR than human c-Src or v-Abl.

Tech Support

Answers to questions you may have can be found in the inhibitor handling instructions. Topics include how to prepare stock solutions, how to store inhibitors, and issues that need special attention for cell-based assays and animal experiments.

AG-490 (Tyrphostin B42) is an inhibitor of EGFR with IC50 of 0.1 μM in cell-free assays, 135-fold more selective for EGFR versus ErbB2, also inhibits JAK2 with no activity to Lck, Lyn, Btk, Syk and Src.